Reamer



LER

M. E. SE

@cfc, 29, 1929.

REAME Filed Aug. 5 1927 2o stances, that reamed-out, spaced-apart Patented Oct. 29, 1929 UNITED s'rA ras- PATENT orr c'a mcmr. I. smm, II WU, rmmvsma. AIBIGIOB '10 KEYSTONE w & 'IQOL 00., mnmnm, PENNSYLVANIA, A CORPORATION 0] ram:-

SILVA-NIL Application a... August so, 1021. mm 80. 210,403.

This invention relates to reamers and aims to provide an i roved long ilot reamer eminently adapte for use as a and tool to ream out perfectly alined spaced apart holes.

This a plication involves an improvement over the invention disclosed in m copending application, Serial No. 566,791, ed June 8, v1922. V In the accompanying drawings:

' Fig. 1 is a side elevational view of a reamer embodying the im rovements;

Fig. 2 is a longitudinal sectional view of the reamer shown in Fig. 1; Fig. 3 is a front end view of the reamer shown in Fig. 1; and

Fig. 4 is a cross sectional view taken on the line 44 of Fig. 2.

It is exceedingly important, in many inoles shall be exactly alined. This is particularly true in the automotive indust%wherein long pilot reamers for such work cipal use. as For some purposes especially where. such reamers are used as hand or. floating tools, for example, in reaming out piston pin bushin s or bearings it is necessary that the front pi 0t of the reamer be long enough to reach 80 through the first hole and part way through the second hole before the reaming begins in order to lead true during the reaming operation. Moreover, in such instances, the front end of the pilot often encounters burrs or other obstacles in the bearings or in the edges of the holes and it is important that it shall have provision for removing such obstacles, thereby permiting the pilot to enter freely without danger of misalinement of the holes. The present invention aims particularly to provide such a reamer that is adapted to accomplish the above named puroses. e p Referring particularly to the drawing, there is shown a reamer aving a shank portion 10 of a diameter slightly less than that of the finished hole which thetool is adapted to ream, this shank being ground within close limits to act as a rear pilot. Below the 5 shank portion-is an elongated fluted portion d their prin- 11 having cutting edges which ma be either straight or spiral as desired. erein, the flute portion is shown as being slotted longitudinall along the bottoms of pairs of diametrically opposed flutes so that the fluted part may be expanded by the usual e anding means which will not be specific y de- At the forward end of the reamer there is shown an elongated pilot portion 12 of such so length as to s an the distance between any two alined ho es which the tool is intended to ream. Thatis to say, the length is such as will enable the reamer to be usedfor a 7 definite group of standard arts of different as diameters or dimensions, t e maximum of which comes within the range of the pilot. Herein, the ilot is shown as being cylindrical and is 'of slightly less diameter than that of the holes which are to be reamed.

To enable the pilot portion to remove any burrs or like obstacles which it may encounter upon entering a hole, it. is shown as having a fluted forward end 13 and forwardly and inwardly tapered side cutting edges 14 pro- 76 vided b relievein and taperin the lands as clear y indicated in Fig. 1. T e taper of the side cutting edges is great enough to insure that the extreme forward end of the pilot will freely enter a rather badly burred, m scarred or uneven hole,, but is not great enough to produce what is known in the trade as a rose end cutter. It has been found by experience that rose end cutters on pilots of this character tend to lead the ilot out as of alinement with the original axis of the holes bein reamed; whereas a slightly tapered end aving side cutting edges only will automatically center itself in a hole while it is removing any burrs or like obstacles that may have been formed in it.

In using the reamer to ream out piston in bushings or bearings for example, (see ig.

2 of the drawing), the front pi ot is inserted in them and turned until ,both holes have been full reamed. Itwill be noted that the front en of the ilot must enter the second hole and be gui ed thereby while the cuthas been reamed and the reamer proper enters the second hole, the shank ortion 10 or rear pilot which is of slight y less diameter than the reamed first hole, will enter 5 it and thereby guide the reamer true into and throu h the second hole. Thus, the reamer lea s true'through both holes during the entire reaming operation so that, when the operation is completed, both holes are neoessarily in perfect alinement and; coaxial with the original holes. Obviously the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, 1 it is not indispensable that all the features of the invention be used conjointly since they may be employed advantageously in various combinations and. subcombinations.

\ What is claimed is:

1. Anexpansibldreamerforpistonpinbearings, bushings and the like comprising a long reari shank constituting a rear pilot; a fluted and expansible intermediate blade section integral with the said shank; and a long 35 cylindrical front 'pilot integral with the blade section and of slightly less diameter than the shank, said pilot having circumferentially spaced longitudinal flutes near the forward end resentin substantiall radial faces 30 and t e lands tween said utes being forwardly and inwardly'tapered at a small inclination and relieved so as to present side cutting edges on] in order to remove any burrs at the entering ends of the holes to be u reamed and accurately center the front pilot therein as the work progresses.

2. An expansible reamer of the character described comprising, in combination, a shank constituting a rear pilot an expansible blade section; an elongated cylindrical front ilot of such length as to span 'the distance etween spaced apart openings to be reamed;

and slightly forwardly tapered side-cutting teeth only terminating at the front end of 5 the front ilot arranged automatically to lead said i ot true or center it in an opening at the en as well asto cut away any burrs around said opening.

In testimony, that I claim thecforegoing as w my own, I have hereto aflixed m si ature.

' MICHAEL I. EI ER. 

